// Copyright 2018-2019 Yubico AB
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <Foundation/Foundation.h>

typedef void (^YKFKVOObservationBlock) (id _Nonnull oldValue, id _Nonnull newValue);

@interface YKFKVOObservation: NSObject

- (nullable instancetype)initWithTarget:(nonnull id)target keyPath:(nonnull NSString *)keyPath callback:(nonnull YKFKVOObservationBlock)callback NS_DESIGNATED_INITIALIZER;
- (nonnull instancetype)init NS_UNAVAILABLE;

@end
